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Goodwill - Additional Information (Detail) $ in Millions |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Oct. 01, 2018 Cash_Generating_Units | Sep. 30, 2018 CAD ($) | Dec. 31, 2018 | Dec. 31, 2017 CAD ($) | Oct. 01, 2017
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Number of cash generating units | Cash_Generating_Units | 7 |  |  |  |
Description of basis on which units recoverable amount has been determined |  |  | Using the fair value less costs of disposal approach |  |
Description of level of fair value hierarchy within which fair value measurement is categorised | Level 3 |  |  |  |
Description of projection | Terminal growth rates based on actual experience and market analysis. Projections are extrapolated beyond five years using a growth rate that does not exceed 3.0%. |  |  |  |
Construction services group [member] | Discontinued operations [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Goodwill impairment charge | $ |  | $ 53.0 |  |  |
Top of range [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Discounted Rate | 17.00% |  |  |  | 15.10%
Percentage of growth rate | 3.00% |  |  |  |
Bottom of range [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Discounted Rate | 9.30% |  |  |  | 8.90%
Consulting Services Global [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Number of cash generating units | Cash_Generating_Units | 3 |  |  |  |
Goodwill disposed | $ |  |  |  | $ 88.1 |
Discounted Rate | 11.20% |  |  |  |
Percentage of growth rate | 3.00% |  |  |  |
Construction Services [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Number of cash generating units | Cash_Generating_Units | 2 |  |  |  |
Consulting Services United States [member] |  |  |  |  |
Disclosure of information for cash-generating units [line items] |  |  |  |  |
Goodwill disposed | $ |  |  |  | $ 106.3 |

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- Definition The description of the basis on which the cash-generating unit's (group of units') recoverable amount has been determined (ie value in use or fair value less costs of disposal). [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_c&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The discount rate applied to cash flow projections for a cash-generating unit (group of units). [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph d -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_v&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph e -Clause v -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_v&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The growth rate used to extrapolate cash flow projections beyond the period covered by the most recent budgets/forecasts for a cash-generating unit (group of units). [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph d -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_iv&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph e -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_iv&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The description of the level of the fair value hierarchy within which the fair value measurement is categorised in its entirety (without giving regard to the observability of 'costs of disposal') for a cash-generating unit (group of units'). [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph e -Clause iiA -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_iiA&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph f -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_f_i&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The explanation of the period over which management has projected cash flows based on financial budgets/forecasts approved by management including, when a period greater than five years is used for a cash-generating unit (group of units), an explanation of why that longer period is justified. [Refer: Cash-generating units [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph d -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_d_iii&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 134 -Subparagraph e -Clause iii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_134_e_iii&doctype=Standard -URIDate 2018-03-16 + Details
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- Definition The amount of goodwill derecognised without having previously been included in a disposal group classified as held for sale. [Refer: Goodwill; Disposal groups classified as held for sale [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2018-01-01 -Paragraph B67 -Subparagraph d -Clause iv -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=3&date=2018-03-01&anchor=para_B67_d_iv&doctype=Appendix&seq=2 -URIDate 2018-03-16 + Details
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- Definition The amount recognised as a reduction of the carrying amount of an asset or cash-generating unit to its recoverable amount. [Refer: Carrying amount [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_b&doctype=Standard -URIDate 2018-03-16 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 36 -IssueDate 2018-01-01 -Paragraph 130 -Subparagraph d -Clause ii -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=36&date=2018-03-01&anchor=para_130_d_ii&doctype=Standard -URIDate 2018-03-16 + Details
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